Control method and apparatus of an ultrasonic motor, and an ultrasonic motor driver and controller

ABSTRACT

A control apparatus of an ultrasonic motor, comprises a driving wave number determining means for determining a driving wave number based on the targeted displacement of a driven object driven by the ultrasonic motor, a normative driving wave generating means for generating continuously normative driving waves in the number of times determined at the driving wave number determining means, inserted an interval determined based on the targeted velocity of the driven object, every at least one cycle of the normative driving waves, and a driving wave generating means for generating driving waves having the predetermined frequency and the predetermined amplitude based on the normative driving waves generated at the normative driving wave generating means.

RELATED APPLICATIONS

This application claims priority of Japanese application serial number2002-366699 and Japanese application serial number 2003-004695, thecontents of both being incorporated herein by reference in theirentirety.

BACKBROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a control method and apparatus of anultrasonic motor, and an ultrasonic motor driver and controller,especially to a control method and apparatus of an ultrasonic motor, andan ultrasonic motor driver and controller enabling to control accuratelythe displacement and/or the velocity of a driven object driven by theultrasonic motor.

2. Description of the Related Art

An ultrasonic motor consists of a piezoelectric element, which makeselastic movement when a voltage is applied across the piezoelectricelement, and an elastic body, which transfers the elastic motion of thepiezoelectric element to a driven object driven by the ultrasonic motor.

The ultrasonic motor drives the driven object linearly, by applying analternative voltage to vibrate the piezoelectric element with theelastic body contacting to the driven object.

When the ultrasonic motor is applied to drive a stage of a microscope,it is necessary to control accurately the displacement and the velocityof the stage in order to put an inspecting object in perspective of themicroscope.

Up until now, the velocity of the driven object was controlled by avoltage, a frequency, and a phase of the electric power applied to theultrasonic motor, and the displacement of the driven object wascontrolled by the number of the driving waves applied to the ultrasonicmotor (See Japanese unexamined patent publication No. 11-150962).

The above-mentioned control method, however, cannot accurately controlthe displacement and/or the velocity of the driven object, because ofthe characteristic difference between individual ultrasonic motors andthe difference of contacting status of the ultrasonic motor to thedriven object.

Therefore, various control methods and apparatuses of the ultrasonicmotor have been proposed to improve control accuracy.

For example, there has been proposed the apparatus to control thevelocity of the driven object by making a means to change the frequencyof the driving waves supplied to the ultrasonic motor active while theamplitude of the driving waves is kept at constant, and a means tochange the amplitude active while the frequency is kept at constant (SeeJapanese Patent No. 3220932)

It is difficult, however, to dissolve the following problems with theabove-mentioned apparatus.

1. The ultrasonic motor cannot accurately control the displacement ofthe driven object, when driving waves are continuously supplied, becausethe friction force changes considerably at the beginning and ending ofthe displacement of the driven object.

2, The relationship between the change of the frequency of the drivingwaves and the change of the velocity of the driven object is not linearbut nonlinear, and the nonlinear characteristic cannot be explicitlyunderstood.

3. The velocity of the driven object becomes faster as the amplitude ofthe driving waves is larger, but the displacement resolution isdeteriorated concurrently because the displacement of the driven objectper one driving wave becomes large.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide acontrol method and apparatus of an ultrasonic motor enabling to controlaccurately the displacement and/or the velocity of a driven objectdriven by an ultrasonic motor.

It is another object of the present invention to provide a ultrasonicmotor driver enabling to control accurately the number of times and theoperating velocity of the ultrasonic motor.

It is a further object of the present invention to provide an ultrasonicmotor controller enabling to control accurately the displacement and/orthe velocity of the driven object driven by the ultrasonic motor.

According to one aspect of the present invention, there is provided acontrol apparatus of an ultrasonic motor, comprising: a driving pulsereceiving means for receiving one or a plurality of driving pulses toenergize an ultrasonic motor which drives a driven object everypredetermined interval; a normative driving wave generating means forgenerating continuously normative driving waves, the numbers of whichare equal to the numbers of driving pulses received at the driving pulsereceiving means multiplied by a predetermined number; and a driving wavegenerating means for generating driving waves having a predeterminedfrequency and a predetermined amplitude based on the normative drivingwaves generated at the normative driving wave generating means.

The controller of the ultrasonic motor thus constructed can accuratelydisplace the driven object, because the driving waves are supplied everya predetermined interval.

According to another aspect of the present invention, there is provideda control apparatus of an ultrasonic motor, comprising: a driving wavenumber determining means for determining a driving wave number based onthe targeted displacement of a driven object driven by the ultrasonicmotor; a normative driving wave generating means for generatingcontinuously normative driving waves in the number of times determinedat the driving wave number determining means, inserted an intervaldetermined based on the targeted velocity of the driven object, every atleast one cycle of the normative driving waves; and a driving wavegenerating means for generating driving waves having the predeterminedfrequency and the predetermined amplitude based on the normative drivingwaves generated at the normative driving wave generating means.

The normative driving wave generating means may make the interval longeras the targeted velocity of the driven object is smaller.

The controller of the ultrasonic motor thus constructed can accuratelydisplace the driven object based on the targeted displacement, becausethe driving waves in the number of times determined based on thetargeted displacement are supplied every a predetermined interval.

According to the further aspect of the present invention, there isprovided a control apparatus of an ultrasonic motor, comprising; adisplacement deviation calculating means for calculating a displacementdeviation defined by a deviation between the targeted displacement of adriven object driven by the ultrasonic motor and the actual displacementof the driven object; a driving wave number determining means fordetermining a driving wave number based on the displacement deviationcalculated at the displacement deviation calculating means; a normativedriving wave generating means for generating continuously normativedriving waves in the number of times determined at the driving wavenumber determining means, inserted an interval determined based on thetargeted velocity of the driven object, every at least one cycle of thenormative driving waves; and a driving wave generating means forgenerating driving waves having the predetermined frequency and thepredetermined amplitude based on the normative driving waves generatedat the normative driving wave generating means.

The normative driving wave generating means may make the interval longeras the targeted velocity of the driven object is smaller.

The controller of the ultrasonic motor thus constructed can accuratelycontrol the displacement of the driven object so that the actualdisplacement corresponds to the targeted displacement, because thedriving waves in the number of times determined based on thedisplacement deviation are supplied every a predetermined interval.

According to a further aspect of the present invention, there isprovided a control apparatus of an ultrasonic motor, comprising; adisplacement deviation calculating means for calculating a displacementdeviation defined by a deviation between the targeted displacement of adriven object driven by the ultrasonic motor and the actual displacementof the driven object; a driving wave number determining means fordetermining a driving wave number based on the displacement deviationcalculated at the displacement deviation calculating means; a velocitydeviation calculating means for calculating a velocity deviation definedby a deviation between the targeted velocity of the driven object andthe actual velocity of the driven object; a normative driving wavegenerating means for generating continuously normative driving waves inthe number of times determined at the driving wave number determiningmeans, inserted an interval determined based on the velocity deviationcalculated at the velocity deviation calculating means, every at leastone cycle of the normative driving waves; and a driving wave generatingmeans for generating driving waves having the predetermined frequencyand the predetermined amplitude based on the normative driving wavesgenerated at the normative driving wave generating means.

The normative driving wave generating means may make the interval longeras the targeted velocity of the driven object is smaller.

The controller of the ultrasonic motor thus constructed can accuratelycontrol the displacement and velocity of the driven object so that theactual displacement and velocity correspond to the targeted displacementand velocity, because the driving waves in the number of timesdetermined based on the displacement deviation are supplied every ainterval determined based on the velocity deviation.

According to a further aspect of the present invention, there isprovided an ultrasonic motor driver, comprising: a driving pulsereceiving part to receive one or a plurality of driving pulses toenergize an ultrasonic motor which drives a driven object everypredetermined interval; a multiplier setting part to set a multiplier; amanual-mode normative driving wave generating part to generatecontinuously manual-mode normative driving waves, the numbers of whichare equal to the numbers of driving pulses received at the driving pulsereceiving part multiplied by the multiplier set at the multipliersetting part; a targeted displacement receiving part to receive atargeted displacement of the driven object; a displacement deviationcalculating part to calculate a displacement deviation defined by adeviation between the targeted displacement received by the targeteddisplacement receiving part and the actual displacement of the drivenobject; a displacement control signal choosing part to choose betweenthe targeted displacement received by said targeted displacementreceiving part and the displacement deviation calculated by thedisplacement deviation calculating part, as a displacement controlsignal; a driving wave number determining part to determine a drivingwave number based on the displacement control signal chosen by thedisplacement control signal choosing part; a targeted velocity receivingpart to receive a targeted velocity of the driven object; a velocitydeviation calculating part to calculate a velocity deviation defined bya deviation between the targeted velocity received by the targetedvelocity receiving part and the actual velocity of the driven object; avelocity control signal choosing part to choose between the targetedvelocity received by the targeted velocity receiving part and thevelocity deviation calculated by the velocity deviation calculatingpart, as a velocity control signal; an auto-mode normative driving wavegenerating part to generate continuously auto-mode normative drivingwaves in the number of times determined by the driving wave numberdetermining part, inserted an interval determined based on the velocitycontrol signal chosen by the velocity control signal choosing part,every at least one cycle of the auto-mode normative driving waves; anormative driving wave choosing part to choose normative driving wavesbetween the manual-mode normative driving waves and the auto-modenormative driving waves; and a driving wave generating part to generatedriving waves having the predetermined frequency and the predeterminedamplitude based on the normative driving waves chosen by the normativedriving wave choosing part.

The normative driving wave generating part may make the interval longeras the targeted velocity of the driven object is smaller.

The driving wave generating part may include either at least one of afrequency changing part to change the frequency of the normative drivingwaves and an amplitude changing part to change the amplitude of thenormative driving waves.

The ultrasonic motor controller such constructed can accurately controlthe driving number of times and the operating velocity of the ultrasonicmotor driving the driven object.

According to a further aspect of the present invention, there isprovided an ultrasonic motor controller, comprising: an ultrasonic motordriver comprised of a driving pulse receiving part to receive one or aplurality of driving pulses to energize an ultrasonic motor which drivesa driven object every predetermined interval, a multiplier setting partto set a multiplier, a manual-mode normative driving wave generatingpart to generate continuously manual-mode normative driving waves, thenumbers of which are equal to the numbers of driving pulses received atthe driving pulse receiving part multiplied by the multiplier set at themultiplier setting part, a targeted displacement receiving part toreceive a targeted-displacement of the driven object, a displacementdeviation calculating part to calculate a displacement deviation definedby a deviation between the targeted displacement received by thetargeted displacement receiving part and the actual displacement of thedriven object, a displacement control signal choosing part to choosebetween the targeted displacement received by the targeted displacementreceiving part and the displacement deviation calculated by saiddisplacement deviation calculating part, based on a displacement controlchoosing signal, a driving wave number determining part to determinedriving wave number based on the displacement control signal chosen bythe displacement control signal choosing part, a targeted velocityreceiving part to receive a targeted velocity of the driven object, avelocity deviation calculating part to calculate a velocity deviationdefined by a deviation between the targeted velocity received by thetargeted velocity receiving part and the actual velocity of the drivenobject, a velocity control signal choosing part to choose between thetargeted velocity received by said targeted velocity receiving part andthe velocity deviation calculated by said velocity deviation calculatingpart, based on a velocity control choosing signal, an auto-modenormative driving wave generating part to generate continuouslyauto-mode normative driving waves in the number of times determined bythe driving wave number determining part, inserted an intervaldetermined based on the velocity control signal chosen by the velocitycontrol signal choosing part, every at least one cycle of the auto-modenormative driving waves, a normative driving wave choosing part tochoose between the manual-mode normative driving waves generated by themanual-mode normative driving waves and the auto-mode normative drivingwaves generated by the auto-mode normative driving waves based on anormative driving wave choosing signal, and a driving wave generatingpart to generate driving waves having the predetermined frequency andthe predetermined amplitude based on the normative driving waves chosenby the normative driving wave choosing part;

a driving pulse generating part to generate the driving pulses suppliedto the driving pulse receiving part; a multiplier changing part tochange a multiplier set at the multiplier setting part; a targeteddisplacement generating part to generate the targeted displacementsupplied to the targeted displacement receiving part; an actualdisplacement measuring part to measure the actual displacement of thedriven object supplied to the displacement deviation calculating part; adisplacement control mode choosing signal outputting part to output thedisplacement control mode choosing signal to the displacement controlsignal choosing part; a targeted velocity generating part to generatethe targeted velocity supplied to the targeted velocity receiving part;an actual velocity measuring part to measure the actual velocity of thedriven object supplied to the velocity deviation calculating part; avelocity control-mode choosing signal outputting part to output thevelocity control-mode choosing signal to the velocity control signalchoosing part; and a normative driving wave choosing signal outputtingpart to output the normative driving wave choosing signal to the anormative driving wave choosing part.

The normative driving wave generating part may make the interval longeras the targeted velocity of the driven object is smaller.

The driving wave generating part may include either at least one of afrequency changing part to change the frequency of the normative drivingwaves and an amplitude changing part to change the amplitude of thenormative driving waves.

The ultrasonic motor controller thus constructed can accurately controlthe displacement and velocity of the driven object driven by theultrasonic motor.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features and advantages of the present invention willbecome apparent as the description proceeds when taken in conjunctionwith the accompanying drawings, in which:

FIG. 1 is a block diagram of a first embodiment of the controller of theultrasonic motor according to the present invention;

FIG. 2 is a block diagram of a microprocessor applied to the controllerof the ultrasonic motor according to the present invention;

FIG. 3 is a block diagram of a second embodiment of the controller ofthe ultrasonic motor according to the present invention;

FIG. 4 is a flowchart of a first control program executed in themicroprocessor of the second embodiment;

FIG. 5 and FIG. 6 are explaining drawings of wave shapes of the drivingwaves;

FIG. 7 is a block diagram of a third embodiment of the controller of theultrasonic motor according to the present invention;

FIG. 8 is a flowchart of a second control program executed in themicroprocessor of the third embodiment;

FIG. 9 is a block diagram of a forth embodiment of the controller of theultrasonic motor according to the present invention;

FIG. 10 is a graph showing a relationship between the velocity deviationand the coefficient β

FIG. 11 is a flowchart of a third control program executed in themicroprocessor of the controller of the forth embodiment;

FIG. 12 is a block diagram of a fifth embodiment of the controller ofthe ultrasonic motor according to the present invention;

FIG. 13A and FIG. 13B are flowcharts of a forth control program executedin the microprocessor of the fifth embodiment;

FIG. 14 is a block diagram of a sixth embodiment of the controller ofthe ultrasonic motor according to the present invention; and

FIG. 15 is a block diagram of a stage control system applying theultrasonic motor controller according the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1, a first embodiment of a control apparatus 1 of anultrasonic motor according to the present invention includes a drivingpulse receiving means 101 for receiving one or a plurality of drivingpulses to energize an ultrasonic motor 62, which drives a driven object61 every predetermined interval, a normative driving wave generatingmeans 102 for generating continuously normative driving waves, thenumbers of which are equal to the numbers of driving pulses received atthe driving pulse receiving means 101 multiplied by a predeterminedmultiplier, and a driving wave generating means 11 for generatingdriving waves having a predetermined frequency and a predeterminedamplitude based on the normative driving waves generated at thenormative driving wave generating means 102.

The control apparatus is comprised of a microprocessor 10, which worksas the driving pulse receiving means 101 and the normative driving wavegenerating means 102, and the driving wave generating means 11 iscomprised of discrete elements.

The driving wave generating means 11 includes a frequency-changing unit111 and an amplitude-changing unit 112.

The microprocessor 10 also works as a targeted frequency setting unit103 and a targeted amplitude setting unit 104.

The microprocessor 10 consists of a CPU 10 b, a memory 10 c, and aninterfaces 10 d, which are connected each other by a bus 10 a. Themicroprocessor 10 fetches driving pulses through the interface 10 d, andoutputs normative driving waves, and the targeted frequency and thetargeted amplitude of the normative driving waves.

The driving pulses are generated at a driving pulse generating part 63,which consists of a rotary encoder, for example, and are transmitted tothe driving pulse receiving means 101 in the microprocessor 10 throughthe interface 10 d.

A multiplier is output from a multiplier setting part 64, which consistsof a potentiometer, for example, and is transmitted to the normativedriving wave generating means 102 in the microprocessor 10 through theinterface 10 d.

The normative driving wave generating means 102 is configured so as todetermine the number of the normative driving waves n as the product ofthe number of driving pulses N received by the driving pulse receivingmeans 102 and the multiplier m set at the multiplier setting part 64based on equation (1).n=mN  (1)

The frequency-changing unit 111 in the driving wave generating means 11is configured so as to generate the driving waves based on the normativedriving waves generated at the normative driving wave generating means102.

The frequency-changing unit 111 is configured so that the frequency ofthe driving waves can be changed by changing the targeted-frequency setat the targeted frequency setting part 103.

The amplitude-changing unit 112 in the driving wave generating means 11is configured so as to generate a first driving waves having the samephase as the driving waves generated at the frequency-changing unit 111,and a second driving waves having a phase difference in 90 degrees tothe driving waves in order to amplify the first driving waves and thesecond driving waves supplied to the ultrasonic motor 62.

The amplitude-changing unit 112 is configured so that the amplitude ofthe amplified first and second driving waves can be changed by changingthe targeted amplitude set at the targeted-amplitude setting part 104.

The first and second driving waves output from the amplitude-changingunit 112 are supplied to the piezoelectric element of the ultrasonicmotor 62. In result, the piezoelectric element moves elliptically, anddrives the driven object 61 linearly.

For example, when 100 driving pulses are generated by operating thedriving pulse generating part 63 every one second, the wave pattern ofthe normative driving waves generated at the normative driving wavegenerating means assumes the pattern of 1000 continuous driving waves towhich a one second interval is added if the multiplier m is 10.

As shown in FIG. 3, a second embodiment of a control apparatus of anultrasonic motor according to the present invention 2 includes a drivingwave number determining means 105 for determining a driving wave numberbased on the targeted displacement of a driven object 61 driven by theultrasonic motor 62, a normative driving wave generating means 102 forgenerating continuously normative driving waves in the number of timesdetermined at the driving wave number determining means 105, inserted aninterval determined based on the targeted velocity of the driven object61, every at least one cycle of the normative driving waves, and adriving wave generating means 11 for generating driving waves having thepredetermined frequency and the predetermined amplitude based on thenormative driving waves generated at the normative driving wavegenerating means 102.

The control apparatus consists of a microprocessor 10, which works asthe driving wave number determining means 105 and the normative drivingwave generating means 102, and the driving wave generating means 11consisting of discrete elements.

The driving wave generating means 11 includes a frequency-changing unit111 and an amplitude-changing unit 112.

The microprocessor 10 also works as a targeted frequency setting part103 and a targeted amplitude setting part 104.

The constituent elements of the second embodiment having the samefunction as the first embodiment are not explained in detail, by givingthe same reference numerals.

Because the microprocessor 10 of this embodiment has the sameconfiguration as the first embodiment, the explanation of theconfiguration of the microprocessor 10 is omitted.

The microprocessor 10 fetches a targeted displacement and a targetedvelocity of the driven object 61 and outputs the normative drivingwaves, the targeted frequency and the targeted amplitude through theinterface 10 d.

The targeted displacement Xd is transferred from the targeteddisplacement setting part 65 consisting of a rotary encoder to thedriving wave number determining means 105 in the microprocessor 10through the interface 10 d.

The driving wave number determining means 105 is configured so as todetermine the number of times n of driving waves supplied to theultrasonic motor 62 as the function of the targeted displacement Xdbased on equation (2).n=f(Xd)  (2)

The targeted velocity Vd is transferred from the targeted velocitysetting part 66 consisting of another rotary encoder to the normativedriving wave generating means 102 in the microprocessor 10 through theinterface 10 d.

The normative driving wave generating means 102 is configured so as todetermine the interval D as the function of the targeted velocity Vdbased on equation (3).D=g(Vd)  (3)

It is necessary to make the interval D longer as the targeted velocitybecomes smaller, and the interval D is a decreasing function of thetargeted velocity Vd. When the period of the normative driving wave isdefined as T, it is preferable to define the interval D as the productof the period T and h. Where, h is a decreasing function of the targetedvelocity Vd.

Therefore, it is preferable to determine the interval D based onequation (4).D=h(Vd)×T  (4)

The normative driving wave generating means 102 is configured so as toinsert the interval D determined based on equation (4), every at leastone cycle of the normative driving waves.

The microprocessor 10 executes the control program represented by theflowchart of FIG. 4, and works as the driving wave number determiningmeans 105, the normative driving wave generating means 102, the targetedfrequency setting means 103, and the targeted amplitude setting means104.

The microprocessor 10 fetches the targeted displacement Xd from thetargeted displacement setting part 65 at step S41, and determines thedriving wave number based on the targeted displacement Xd at step S42.

Further, the microprocessor 10 fetches the targeted velocity Vd from thetargeted velocity setting part 66 at step S43, and generates thenormative driving waves in which the interval determined based on thetargeted velocity Vd every at least one cycle of the normative drivingwaves at step S44.

Finally, the microprocessor 10 outputs the normative driving waves atstep S45, the targeted frequency at step S46, and the targeted amplitudeat step S47.

When the interval D is inserted every one cycle of the normative drivingwave, the normative driving waves become continuous waves having aperiod T as shown in FIG. 5A, if h=0.

The interval having a 0.25 T length is inserted every one cycle of thenormative driving wave as shown in FIG. 5B if h=0.25.

The interval having a 0.5 T length is inserted every one cycle of thenormative driving wave as shown in FIG. 5C if h=0.5.

The interval may be inserted every two cycles of the normative drivingwaves as shown in FIG. 6A, and may be inserted every four cycles of thenormative driving waves as shown in FIG. 6B.

Because the driving wave generating means 11 of this embodiment has thesame configuration and function as the first embodiment, the explanationis omitted.

As shown in FIG. 7, a third embodiment of a control apparatus of anultrasonic motor according to the present invention 3 includes adisplacement deviation calculating means 106 for calculating adisplacement deviation defined by a deviation between the targeteddisplacement of a driven object 61 driven by the ultrasonic motor 62 andthe actual displacement of the driven object 61, a driving wave numberdetermining means 105 for determining a driving wave number based on thedisplacement deviation calculated at the displacement deviationcalculating means 106, a normative driving wave generating means 102 forgenerating continuously normative driving waves in the number of timesdetermined at the driving wave number determining means 105, inserted aninterval determined based on the targeted velocity of the driven object61, every at least one cycle of the normative driving waves, and adriving wave generating means 11 for generating driving waves having thepredetermined frequency and the predetermined amplitude based on thenormative driving waves generated at the normative driving wavegenerating means 102.

The control apparatus consists of a microprocessor 10, which works asthe displacement deviation calculating means 106, the driving wavenumber determining means 105 and the normative driving wave generatingmeans 102, and the driving wave generating means 11 consisting ofdiscrete elements.

The driving wave generating means 11 includes a frequency-changing unit111 and an amplitude-changing unit 112.

The microprocessor 10 also works as a frequency setting part 103 and anamplitude setting part 104.

The constituent elements of the third embodiment having the samefunction as the second embodiment are not explained in detail, by givingthe same reference numerals.

Because the hardware configuration of the microprocessor 10 is the sameas the first embodiment, the explanation of the hardware configurationis omitted.

The targeted displacement Xd is transferred from the targeteddisplacement setting part 65 consisting of a rotary encoder to thedisplacement deviation calculating means 106 in the microprocessor 10through the interface 10 d.

An actual displacement measuring means 67 consisting of a linear encoderto measure the actual displacement of the driven object 61 is attachedto the driven object 61, and feedbacks the actual displacement Xa of thedriven object 61 to the displacement deviation calculating means 106.

The driving wave number determining means 105 is configured so as todetermine the number n of driving waves supplied to the ultrasonic motor62 as the function of the displacement deviation ed based on thefollowing equation (5).n=f(ed)  (5)

The targeted velocity Vd is transferred from the targeted velocitysetting part 66 consisting of another rotary encoder to the normativedriving wave generating means 102 in the microprocessor 10 through theinterface 10 d. The normative driving wave generating means 102 isconfigured so as to determine the interval D as the function of thetargeted velocity Vd based on equation (6).D=h(Vd)T  (6)

The normative driving wave generating means 102 is configured so as toinsert the interval D determined based on equation (6), every at leastone cycle of the normative driving waves.

The microprocessor 10 executes the control program represented by theflowchart of FIG. 8, and functions as the displacement deviationcalculating means 106, the driving wave number determining means 105,the normative driving wave generating means 102, the targeted frequencysetting means 103, and the targeted amplitude setting means 104.

Because the program shown in FIG. 8 is the program shown in FIG. 4 towhich step S81 and step S82 are added, the program behavior will beexplained focus on step S81 and step S82.

The microprocessor 10 fetches the actual displacement Xa of the drivenobject 61 measured by the displacement measuring means 67 at step S81after fetching the targeted displacement at step S41.

The microprocessor 10 subtracts the actual displacement Xa from thetargeted displacement Xd to calculate the displacement deviation at stepS82, and determines the driving wave number n based on equation (7).n=f(ed)  (7)

The program behavior after step S43 is the same as that of FIG. 3, andthe explanation is omitted.

The normative driving waves generated by the normative driving wavegenerating means 102 is supplied to the driving wave generating means11, but the explanation of the driving wave generating means 11 isomitted because its behavior is the same as the controller according tothe second invention.

As shown in FIG. 9, a forth embodiment of a control apparatus of anultrasonic motor 4 according to the present invention includes adisplacement deviation calculating means 106 for calculating adisplacement deviation defined by a deviation between the targeteddisplacement of a driven object 61 driven by the ultrasonic motor 62 andthe actual displacement of the driven object 61, a driving wave numberdetermining means 105 for determining a driving wave number based on thedisplacement deviation calculated at the displacement deviationcalculating means 106, a velocity deviation calculating means 107 forcalculating a velocity deviation defined by a deviation between thetargeted velocity of the driven object 61 and the actual velocity of thedriven object 61, a normative driving wave generating means 102 forgenerating continuously normative driving waves in the number of timesdetermined at the driving wave number determining means 105, inserted aninterval determined based on the velocity deviation calculated at thevelocity deviation calculating means 107, every at least one cycle ofthe normative driving waves, and a driving wave generating means 11 forgenerating driving waves having the predetermined frequency and thepredetermined amplitude based on the normative driving waves generatedat the normative driving wave generating means 106.

The control apparatus is comprised of a microprocessor 10, which worksas the displacement deviation calculating means 106, the driving wavenumber determining means 105, the normative driving wave generatingmeans 102 and the velocity displacement calculating means 107, and thedriving wave generating means 11 consist of discrete elements.

The driving wave generating means 11 includes a frequency-changing unit111 and an amplitude-changing unit 112.

Further, the microprocessor 10 works as a frequency setting part 103 andan amplitude setting part 104.

The constituent elements having the same function as the controller ofthe ultrasonic motor according to the third invention are not explainedin detail, by giving the same reference numerals.

Because the hardware constitution of the microprocessor 10 is the sameas the first embodiment of the ultrasonic motor, the explanation of thehardware constitution of the microprocessor 10 is omitted.

The targeted displacement Xd is transferred from the targeteddisplacement setting part 65 consisting of a rotary encoder to thedisplacement deviation calculating means 106 in the microprocessor 10through the interface 10 d.

An actual displacement measuring means 67 configured by a linear encoderto measure the actual displacement of the driven object 61 is attachedto the driven object 61, and feedbacks the actual displacement Xa of thedriven object 61 to the displacement deviation calculating means 106.

The displacement deviation calculating means 106 calculates adisplacement deviation defined by the deviation between the targeteddisplacement Xd and the actual displacement Xa.

The driving wave number determining means 105 is configured so as todetermine the number n of driving waves supplied to the ultrasonic motor61 as the function of the displacement deviation Dd based on thefollowing equation (8).n=f(Dd)  (8)

The targeted velocity Vd is transferred from the targeted velocitysetting part 66 consisting of another rotary encoder to the velocitydeviation calculating means 107 in the microprocessor 10 through theinterface 10 d.

An actual velocity measuring means 68 to measure the actual velocity ofthe driven object 61 is attached to the driven object 61, and feedbacksthe actual velocity Va of the driven object 61 to the velocity deviationcalculating means 107.

The actual velocity may be determined by differentiating the actualdisplacement measured by the actual displacement measuring means 67 withrespect to time, or by using a known observer.

The velocity deviation calculating means 107 calculates a velocitydeviation Dv defined by the deviation between the targeted velocity Vdand the actual velocity Va supplied to the normative driving wavegenerating means 102.

The normative driving wave generating means 102 is configured so as todetermine the interval D as the function of the velocity deviation Dv.

Actually, the interval D is calculated by compensating a normativeinterval Do with a compensating factor B which is a function of thevelocity deviation Dv based on equation (9).D=Do(1−B)  (9)

The compensating factor B is defined as an increasing function of thevelocity deviation Dv as shown in FIG. 10.

The normative driving wave generating means 102 is configured so as togenerate the normative driving waves by inserting the interval Ddetermined based on the equation (9), every at least one cycle of thenormative driving waves.

The microprocessor 10 executes the program shown by the flowchart ofFIG. 11, and functions as the displacement deviation calculating means106, the driving wave number determining means 105, the normativedriving wave generating means 102, the velocity deviation calculatingmeans 107, the targeted frequency setting means 103, and the targetedamplitude setting means 104.

Because the program shown in FIG. 11 is the program shown in FIG. 8 towhich step S111 and step S112 are added, the program behavior will beexplained focus on step S111 and step S112.

Because the program behavior from step S41 to step S43 has beenexplained referring the flowchart shown in FIG. 8, the explanation isomitted.

The microprocessor 10 fetches the actual velocity Va of the drivenobject 61 measured by the actual velocity measuring means 68 at stepS111 after fetching the targeted velocity Vd at step S43.

The microprocessor 10 subtracts the actual velocity Va from the targetedvelocity Vd to calculate the velocity deviation Dv at step S112, anddetermines the interval D based on equation (10) at step S44.D=Do(1−B)  (10)

Because the program behavior after step S45 has been explained referringthe flowchart shown in FIG. 8, the explanation is omitted.

The normative driving waves generated by the normative driving wavegenerating means 102 is supplied to the driving wave generating means11, and the explanation of the driving wave generating means 11 isomitted because its behavior is the same as the controller according tothe second invention.

As shown in FIG. 12, a fifth embodiment of a control apparatus of anultrasonic motor according to the present invention includes a drivingpulse receiving part 121 to receive one or a plurality of driving pulsesto energize an ultrasonic motor 16 which drives a driven object 61 everypredetermined interval, a multiplier setting part 151 to set amultiplier, a manual-mode normative driving wave generating part 122 togenerate continuously manual-mode normative driving waves, the numbersof which are equal to the numbers of driving pulses received at thedriving pulse receiving part 121 multiplied by the multiplier set at themultiplier setting part 151.

The fifth embodiment further includes a targeted displacement receivingpart 123 to receive a targeted displacement of the driven object 61, adisplacement deviation calculating part 124 to calculate a displacementdeviation defined by a deviation between the targeted displacementreceived by the targeted displacement receiving part 123 and the actualdisplacement of the driven object 61, a displacement control signalchoosing part 125 to choose between the targeted displacement receivedby the targeted displacement receiving part 123 and the displacementdeviation calculated by the displacement deviation calculating part 124,as a displacement control signal, a driving wave number determining part126 to determine a driving wave number based on the displacement controlsignal chosen by the displacement control signal choosing part 125.

The fifth embodiment further includes a targeted velocity receiving part127 to receive a targeted velocity of the driven object 61, a velocitydeviation calculating part 128 to calculate a velocity deviation definedby a deviation between the targeted velocity received by the targetedvelocity receiving part 127 and the actual velocity of the driven object61, a velocity control signal choosing part 129 to choose between thetargeted velocity received by said targeted velocity receiving part 127and the velocity deviation calculated by the velocity deviationcalculating part 128, as a velocity control signal, an auto-modenormative driving wave generating part 130 to generate continuouslyauto-mode normative driving waves in the number of times determined bythe driving wave number determining part 126, inserted an intervaldetermined based on the velocity control signal chosen by the velocitycontrol signal choosing part 129, every at least one cycle of theauto-mode normative driving waves.

The fifth embodiment further includes a normative driving wave choosingpart 131 to choose normative driving waves between the manual-modenormative driving waves generated by the manual-mode normative drivingwave generating part 122 and the auto-mode normative driving wavesgenerated by the auto-mode normative driving wave generating part 139,and a driving wave generating part 14 to generate driving waves havingthe predetermined frequency and the predetermined amplitude based on thenormative driving waves chosen by said normative driving wave choosingpart.

The control apparatus is comprised of a microprocessor 12, and thedriving wave generating means 14 consists of discrete elements.

The driving pulse receiving part 121 receives the driving pulsesgenerated by the driving pulse generating part consisting of a rotaryencoder to output the driving pulses to the manual-mode normativedriving wave generating means 122.

The manual-mode normative driving wave generating means 122 multipliesthe number of the driving pulses by the multiplier set at the multipliersetting part 151 to output the product to one terminal of the normativedriving wave choosing part 131.

The targeted displacement receiving part 123 receives the targeteddisplacement generated by the targeted displacement generating partconsisting of a rotary encoder, and outputs the targeted displacement tothe displacement deviation calculating part 124 and one terminal of thedisplacement control signal choosing part 125.

The displacement deviation calculating part 124 calculates thedisplacement deviation Dd defined by the deviation between the targeteddisplacement Xd and the actual displacement Xa fetched from the actualdisplacement receiving part 152 to output the displacement deviation Ddto other terminal of the displacement control mode choosing part 125.

The displacement control signal choosing part 125 outputs the targeteddisplacement Xd or the displacement deviation Dd depending on thedisplacement control mode choosing signal received by the displacementcontrol-mode choosing signal receiving part 153.

When the targeted displacement control mode is selected, the drivingwave number determining part 126 determines the driving wave number n asthe function of the targeted displacement Xd based on equation (11), andoutputs the driving wave number n to the auto-mode normative drivingwave generating part 130.n=f(Xd)  (11)

When the displacement deviation control mode is selected, the drivingwave number determining part 126 determines the driving wave number n asthe function of the displacement deviation Dd based on equation (12),and outputs the driving wave number n to the auto-mode normative drivingwave generating part 130.n=f(Dd)  (12)

The targeted velocity receiving part 127 receives the targeted velocitygenerated by the targeted velocity generating part consisting of arotary encoder, and outputs the targeted velocity to the velocitydeviation calculating part 128 and one terminal of the velocity controlsignal choosing part 129.

The velocity deviation calculating part 128 calculates the velocitydeviation Dv defined by the deviation between the targeted velocity Vdand the actual velocity Va fetched from the actual velocity receivingpart 154 to output the velocity deviation Dv to other terminal of thevelocity control mode choosing part 129.

The velocity control signal choosing part 129 outputs the targeteddisplacement Xd or the displacement deviation Dd depending on thedisplacement control mode choosing signal received by the displacementcontrol signal choosing signal receiving part 155.

When the targeted velocity control mode is selected, the auto-modenormative driving wave generating part 130 generates the auto-modedriving waves by inserting the interval D determined based on equation(13), which is a function of the targeted velocity Vd, every at leastone cycle of the normative driving waves.D=g(Vd)  (13)

When the velocity deviation control mode is selected, the auto-modenormative driving wave generating part 130 generates the auto-modedriving waves by inserting the interval D determined based on equation(14), which is a function of the velocity deviation Dv, every at leastone cycle of the normative driving waves.D=g(Dv)  (14)

The normative driving wave generating part 130 is configured so as togenerate the auto-mode normative driving waves by inserting the intervalD, every at least one cycle of the normative driving waves in the numberof times determined by the driving wave number determining part 126 tooutput the auto-mode normative driving wave to another terminal of thenormative driving wave choosing part 131.

The normative driving wave choosing part 131 outputs the manual-modenormative driving waves or the auto-mode normative driving waves to thedriving wave generating part 14, depending to the manual-auto modeselecting signal received by the manual-auto mode selecting signalreceiving part 156.

The driving wave generating part 14 includes a frequency-changing unit141 and an amplitude-changing unit 142.

The frequency changing unit 141 is configured so as to generate a firstdriving waves having the same phase as the normative driving wavesselected at the normative driving wave choosing part 131, and a seconddriving waves having a phase difference in 90 degrees to the normativedriving waves.

The amplitude-changing unit 142 is configured so as to amplify the firstdriving waves and the second driving waves to supply them to theultrasonic motor 62.

The frequency of the amplified first and second driving waves can bemodified by changing the targeted frequency set at the targetedfrequency setting part 157.

The amplitude of the amplified first and second driving waves can bemodified by changing the targeted amplitude set at the targetedamplitude setting part 158.

The first and second driving waves output from the power amplifying unit142 are supplied to the piezoelectric element of the ultrasonic motor 62at right angles each other. In result, the piezoelectric element moveselliptically, and drives the driven object 61 linearly.

The microprocessor 12 executes the program shown in FIG. 13 to generatethe normative driving waves.

The microprocessor 10 fetches the normative driving wave choosing signalat step S131, and determines whether or not the auto-mode is chosen atstep S132.

The microprocessor 10 fetches the targeted displacement Xd at step S41and the displacement control-mode choosing signal at step 133, anddetermines whether or not the displacement feedback mode is selected atstep S134, when the microprocessor 12 determines that the auto-mode ischosen.

The microprocessor 10 fetches the actual displacement of the drivenobject 61 at step S81, calculates the displacement deviation defined bythe deviation between the targeted displacement and the actualdisplacement at step S82, and determines the driving wave number n basedon the displacement deviation at step S42, when the microprocessor 12determines that the displacement feedback mode is selected.

The microprocessor 10 determines the driving wave number based on thetargeted displacement at step S138, when the microprocessor determinedthat the displacement feedback mode is not selected.

The microprocessor 12 fetches the targeted velocity Vd at step S43, andthe velocity control-mode choosing signal at step S135, and determineswhether or not the velocity feedback mode is chosen at step S136.

The microprocessor 10 fetches the actual velocity of the driven object61 at step S111, calculates the velocity deviation defined as thedeviation between the targeted velocity and the actual velocity at stepS112, and generates the auto-mode normative driving waves in which theinterval determined based on the velocity deviation is inserted every atleast one cycle of the normative driving waves at step S137, when themicroprocessor 12 determines that the velocity feedback mode is chosen.

The microprocessor 10 generates the auto-mode normative driving waves inwhich the interval determined based on the targeted velocity is insertedevery at least one cycle of the normative driving waves at step S139,when the microprocessor 12 determines that the velocity feedback mode isnot chosen.

On the other hand, the microprocessor 12 fetches the driving pulses atstep S140, and the multiplier at step S141, when the microprocessor 12determines that the manual mode is chosen.

The microprocessor 12 multiplies the number of the driving pulses by themultiplier at step S142, and generates the manual-mode normative drivingwaves in the number of times equal to the product at step S143.

At step S45, the microprocessor 12 outputs the auto-mode normativedriving waves generated at step S137 or step S139, when the auto mode isselected.

At step S45, the microprocessor 12 outputs the manual-mode normativedriving waves generated at step S143, when the manual-mode is selected.

Finally, the microprocessor 12 outputs the targeted frequency at stepS46, and the targeted amplitude at step S47.

In the above description, the embodiment in which one ultrasonic motordriver moves the driven object with respect to a specific one directionis explained.

One ultrasonic motor driver can control a plurality of ultrasonicmotors, when the driven object is moved with respect to a plurality ofdirections or axes.

In the above description, the ultrasonic motor driver applying thecontrol apparatus of the ultrasonic motor according to the forthinvention, a person with ordinary skill in the art can understand thatthe control apparatus of the ultrasonic motor according to one of thefirst, the second, or the third invention may be applied to theultrasonic motor driver.

It is possible to configure a ultrasonic motor controller as shown inFIG. 14, by adopting the above-mentioned ultrasonic motor driver.

An ultrasonic motor controller according to a sixth invention includesnot only the ultrasonic motor driver according to the fifth invention,but also a driving pulse generating part 71 such as a rotary encoder togenerate driving pulses supplied to the driving pulse receiving part121, a multiplier changing part 72 to change the multiplier set at themultiplier setting part 151, an actual displacement measuring part 67 tomeasure the actual displacement of the driven object 61, an actualvelocity measuring part 68 to measure the actual velocity of the drivenobject 61, and an operation controlling part 73 functioning as atargeted displacement generating part, a targeted velocity generatingpart, a displacement control-mode choosing signal outputting part, avelocity control-mode choosing signal outputting part, and a normativedriving wave choosing signal outputting part.

To the operation controlling part 73, a keyboard 74, a display panel 75,a buzzer 76, and a communication interface 77 are connected.

The operation controlling part 73 controls the ultrasonic motor driver12 based on the operation signals input from the keyboard 74, displaysthe operating status on the display panel 75, and activates the buzzerif required.

The operation controlling part 73 can be connected to a personalcomputer and/or an instrument using RS-232C or GP-IP though thecommunication interface 77.

Therefore, the displacement of the driven object may be set by thepersonal computer, and the auto-manual mode, the displacementcontrol-mode and the velocity control-mode may be changed by thepersonal computer.

The ultrasonic motor controller 6 according to the present inventionincludes an electric power equipment to generate a first electric powerfor driving the ultrasonic motor driver and a second electric power forsupplying to the ultrasonic motor.

In the above description, the ultrasonic motor controller 6 moves thedriven object 61 with respect to a specific one direction, but theultrasonic motor controller 6 may move the driven object with respect toa plurality of directions and/or axes.

When the ultrasonic motor controller moves the stage of the microscopealong the X-axis and Y-axis, two driving waves for driving theultrasonic motor output from the ultrasonic motor controller 7 aresupplied to the X-axis ultrasonic motor 81 which moves the stage 8 tothe X-axis direction, and the Y-axis ultrasonic motor 82 which moves thestage 8 to the Y-axis direction shown in FIG. 15.

The X-axis displacement measured by the linear encoder 83 attached tothe X-axis of the stage 8, and the Y-axis displacement measured by thelinear encoder 84 attached to the Y-axis of the stage 8 are fed back tothe ultrasonic motor controller 7. In this system, the velocity feedbackis not applied.

The ultrasonic motor controller 7 is connected to a personal computer 85through RS-232C, and the personal computer 85 works as a maintenancetool and/or an operation tool.

The ultrasonic motor controller 7 may be connected to measuringinstruments not shown in FIG. 15, in order to monitor the operatingstatus of the ultrasonic motor controller 7.

In the above description, the multiplier set in the multiplier settingpart 151 is changed by the multiplier changing part 72, but themultiplier may be changed by the operation controlling part 73.

In the above description, the ultrasonic motor controller applying theultrasonic motor driver according to the fifth embodiment, a person withordinary skill in the art can easily understand that the ultrasonicmotor controller can be configured with the ultrasonic motor driverapplying one of the first to the third embodiment.

1-25. (canceled)
 26. An ultrasonic motor controller, comprising: anultrasonic motor driver comprised of a driving pulse receiving part toreceive one or a plurality of driving pulses to energize an ultrasonicmotor which drives a driven object every predetermined interval, amultiplier setting part to set a multiplier, a manual-mode normativedriving wave generating part to generate continuously manual-modenormative driving waves, the numbers of which are equal to the numbersof driving pulses received at said driving pulse receiving partmultiplied by the multiplier set at said multiplier setting part, and adriving wave generating part to generate driving waves having apredetermined frequency and a predetermined amplitude based on themanual-mode normative driving waves generated at said manual-modenormative driving wave generating part; a driving pulse generating partto generate the driving pulses supplied to said driving pulse receivingpart; and a multiplier changing part to change the multiplier set atsaid multiplier setting part.
 27. An ultrasonic motor controller,comprising: an ultrasonic motor driver comprised of a targeteddisplacement receiving part to receive a targeted displacement of adriven object driven by an ultrasonic motor, a driving wave numberdetermining part to determine a driving wave number based on thetargeted displacement received by said targeted displacement receivingpart, a targeted velocity receiving part to receive a targeted velocityof the driven object, an auto-mode normative driving wave generatingpart to generate continuously auto-mode normative driving waves in thenumber of times determined by said driving wave number determining part,inserted an interval determined based on the targeted velocity receivedby said targeted velocity receiving part, every at least one cycle ofthe auto-mode normative driving waves, and a driving wave generatingpart to generate driving waves having the predetermined frequency andthe predetermined amplitude based on the auto-mode normative drivingwaves generated at said auto-mode normative driving wave generatingpart; a targeted displacement generating part to generate the targeteddisplacement supplied to said targeted displacement receiving part; anda targeted velocity generating part to generate the targeted velocitysupplied to said targeted velocity receiving part.
 28. An ultrasonicmotor controller as set forth in claim 27, wherein said auto-modenormative driving wave generating part makes the interval longer as thetargeted velocity of the driven object is small.
 29. An ultrasonic motorcontroller, comprising: an ultrasonic motor driver comprised of atargeted displacement receiving part to receive a targeted displacementof a driven object driven by an ultrasonic motor, a displacementdeviation calculating part to calculate a displacement deviation definedby a deviation between the targeted displacement received by saidtargeted displacement receiving part and the actual displacement of thedriven object, a driving wave number determining part to determine adriving wave number based on the displacement deviation calculated bysaid displacement deviation calculating part, a targeted velocityreceiving part to receive a targeted velocity of the driven object, anauto-mode normative driving wave generating part to generatecontinuously auto-mode normative driving waves in the number of timesdetermined by said driving wave number determining part, inserted aninterval determined based on the targeted velocity received by saidtargeted velocity receiving part, every at least one cycle of thenormative driving waves, and a driving wave generating part to generatedriving waves having the predetermined frequency and the predeterminedamplitude based on the auto-mode normative driving waves generated atsaid auto-mode normative driving wave generating part; a targeteddisplacement generating part to generate the targeted displacementsupplied to said targeted displacement receiving part; an actualdisplacement measuring part to measure the actual displacement of thedriven object supplied to said displacement deviation calculating part;and a targeted velocity generating part to generate the targetedvelocity supplied to said targeted velocity receiving part.
 30. Anultrasonic motor controller as set forth in claim 29, wherein saidauto-mode normative driving wave generating part makes the intervallonger as the targeted velocity of the driven object is small.
 31. Anultrasonic motor controller, comprising: an ultrasonic motor drivercomprised of a targeted displacement receiving part to receive atargeted displacement of a driven object driven by an ultrasonic motor,a displacement deviation calculating part to calculate a displacementdeviation defined by a deviation between the targeted displacementreceived by said targeted displacement receiving part and the actualdisplacement of the driven object, a driving wave number determiningpart to determine driving wave numbers based on the displacementdeviation calculated by said displacement deviation calculating part, atargeted velocity receiving part to receive a targeted velocity of thedriven object, a velocity deviation calculating part to calculate avelocity deviation defined by a deviation between the targeted velocityreceived by said targeted velocity receiving part and the actualvelocity of the driven object, an auto-mode normative driving wavegenerating part to generate continuously auto-mode normative drivingwaves in the number of times determined by said driving wave numberdetermining part, inserted an interval determined based on the velocitydeviation calculated by said velocity deviation calculating part, everyat least one cycle of the auto-mode normative driving waves, and adriving wave generating part to generate driving waves having thepredetermined frequency and the predetermined amplitude based on theauto-mode normative driving waves generated at said auto-mode normativedriving wave generating part; a targeted displacement generating part togenerate the targeted displacement supplied to said targeteddisplacement receiving part; an actual displacement measuring part tomeasure the actual displacement of the driven object supplied to saiddisplacement deviation calculating part; a targeted velocity generatingpart to generate the targeted velocity supplied to said targetedvelocity receiving part; and an actual velocity measuring part tomeasure the actual velocity of the driven object supplied to saidvelocity deviation calculating part.
 32. An ultrasonic motor controlleras set forth in claim 31, wherein said auto-mode normative driving wavegenerating part makes the interval longer as the velocity deviation issmall.
 33. An ultrasonic motor controller, comprising: an ultrasonicmotor driver comprised of a driving pulse receiving part to receive oneor a plurality of driving pulses to energize an ultrasonic motor whichdrives a driven object every predetermined interval, a multipliersetting part to set a multiplier, a manual-mode normative driving wavegenerating part to generate continuously manual-mode normative drivingwaves, the numbers of which are equal to the numbers of driving pulsesreceived at said driving pulse receiving part multiplied by themultiplier set at said multiplier setting part, a targeted displacementreceiving part to receive a targeted displacement of the driven object,a displacement deviation calculating part to calculate a displacementdeviation defined by a deviation between the targeted displacementreceived by said targeted displacement receiving part and the actualdisplacement of the driven object, a displacement control signalchoosing part to choose between the targeted displacement received bysaid targeted displacement receiving part and the displacement deviationcalculated by said displacement deviation calculating part, based on adisplacement control choosing signal, a driving wave number determiningpart to determine driving wave number based on the displacement controlsignal chosen by said displacement control signal choosing part, atargeted velocity receiving part to receive a targeted velocity of thedriven object, a velocity deviation calculating part to calculate avelocity deviation defined by a deviation between the targeted velocityreceived by said targeted velocity receiving part and the actualvelocity of the driven object, a velocity control signal choosing partto choose between the targeted velocity received by said targetedvelocity receiving part and the velocity deviation calculated by saidvelocity deviation calculating part, based on a velocity controlchoosing signal, an auto-mode normative driving wave generating part togenerate continuously auto-mode normative driving waves in the number oftimes determined by said driving wave number determining part, insertedan interval determined based on the velocity control signal chosen bysaid velocity control signal choosing part, every at least one cycle ofthe auto-mode normative driving waves, a normative driving wave choosingpart to choose between the manual-mode normative driving waves generatedby said manual-mode normative driving wave generating part and theauto-mode normative driving waves generated by said auto-mode normativedriving wave generating part based on a normative driving wave choosingsignal, and a driving wave generating part to generate driving waveshaving the predetermined frequency and the predetermined amplitude basedon the normative driving waves chosen by said normative driving wavechoosing part; a driving pulse generating part to generate the drivingpulses supplied to said driving pulse receiving part; a multiplierchanging part to change a multiplier set at said multiplier settingpart; a targeted displacement generating part to generate the targeteddisplacement supplied to said targeted displacement receiving part; anactual displacement measuring part to measure the actual displacement ofthe driven object supplied to said displacement deviation calculatingpart; a displacement control-mode choosing signal outputting part tooutput the displacement control-mode choosing signal to saiddisplacement control signal choosing part; a targeted velocitygenerating part to generate the targeted velocity supplied to saidtargeted velocity receiving part; an actual velocity measuring part tomeasure the actual velocity of the driven object supplied to saidvelocity deviation calculating part; a velocity control-mode choosingsignal outputting part to output the velocity control-mode choosingsignal to said velocity control signal choosing part; and a normativedriving wave choosing signal outputting part to output the normativedriving wave choosing signal to said a normative driving wave choosingpart.
 34. An ultrasonic motor controller as set forth in claim 33,wherein said auto-mode normative driving wave generating part makes theinterval longer as the velocity control signal is small.
 35. Anultrasonic motor controller as set forth in one of claims 26 to 34,wherein said driving wave generating part further comprising at leasteither one of a frequency changing part to change the frequency of thenormative driving waves and an amplitude changing part to change theamplitude of the normative driving waves.